Spotlight on SAP ASE 2.12 - User Guide

Term

Definition

A
 

Adaptive Server

The server in the ASE client/server architecture, Adaptive Server manges multiple databases and multiple users, keeps track of the actual location of data on disks, maintains mapping of logical data description to physical data storage, and maintains data caches and procedure caches in memory.
 

Alarm

The mechanism by which Spotlight® on SAP ASE alerts you to a condition that might be a problem in your ASE instance. While an alarm is active, the color of icons on the main screen will change.

Application

A client program that interacts with Adaptive Server. Specifically, an application name refers to the "program_name" column in a sysprocesses table entry. The client libraries provide a mechanism to specify the "program_name" of an application.

ASE

Adaptive Server Enterprise. See Adaptive Server.

Authentication

The process of identifying and verifying a user who is attempting to establish an ASE session. Can be either a Windows Authentication or ASE Authentication. With Windows Authentication (trusted logins), ASE uses Windows security mechanisms to determine who the user is and what they have access to. With ASE Authentication, users must pass an ASE login and password that is validated against an ASE system table. ASE can be configured to allow just Windows Authentication, or both Windows and ASE Authentication (Mixed mode).

B

Backup Server

Performs local or remote backups (dumps) and restored (loads) on selected databases and transaction logs on behalf of Adaptive Server. A Backup Server must be running on the same system as Adaptive Server.

C

Cache hit ratio

For many processes, Adaptive Server uses an in-memory cache. The cache hit ratio is the percentage of times a needed page or result was found in the cache. For data pages, the cache hit ratio is the percentage of page requests that are serviced by the data cache compared to requests that require disk I/O.

Calibration

The process by which Spotlight® on SAP ASE determines the maximum and minimum values for every dataflow on the main screen, by observing data moving through your database system. This information helps Spotlight® on SAP ASE display the dataflows correctly.

Chart

A graphical representation of a statistic over a period of time. One or more statistics may be shown on the same chart.

Client

The user's side of a client/server arrangement; can refer to the software making calls to the server or to the machine running the client software.

Client/Server architecture

A computer system architecture in which clients request a service and a server provides that service. Each machine can then specialize in the tasks it is best suited for.

Container

Determines how an event processor interprets the sequence of bytes that makes up the event body.

D

Data cache

An area of memory within Adaptive Server that contains the in-memory images of database pages, as well as the data structures required to manage the pages. Each cache is given a unique name that is issued for configuration purposes. By default, Adaptive Server has a single cache named "default data cache." Caches configured by users are called "user-defined caches." Data caches are also referred to as buffer caches. 

Data file

A file that is one part of the "data" portion of ASE database. Stores all data such as tables, rows, stored procedures, and indexes. Each database will have one or more data files. Each file belongs to only one database.

Database

A collection of tables and other objects. Each database contains a data portion and a log portion. The data portion contains all tables, rows, indexes, etc., and resides on at least one data file. The log portion tracks updates to the data, and aids recovery. Logs reside on one or more log files.

DataFlow

A Dataflow shows you the current level of activity. As the rate of data transfer increases, so too does the speed of the flow. If the statistic represented by the flow moves to another threshold, the flow may change color. The combination of movement and color makes it easy to spot congested areas. A graph sits on top of the flow and shows you how the load has varied over time.

DBA

Database Administrator. The person who maintains the database or server in your organization.

Deadlock

A deadlock occurs when each of two user processes has a lock on a separate data page, index page, or table, and each wants to acquire a lock on the same page or table locked by the other process. When this happens, the first process is waiting for the second process to release the lock, but the second process will not release it until the lock on the first process's object is released.

Disk device

Once initialized within Adaptive Server, a disk device (sometimes referred to as a database device) stores the objects (tables, indexes, etc.) that make up databases. A disk device does not necessarily have to refer to a physical device. It can be defined as any piece of a disk or a file in the file system that is used to store databases and their objects.

Device

Any piece of disk (such as a partition) or a file in the file system used to store databases and their objects.

Device I/O

The action of reading to or writing from a database device.

Drilldown

A Spotlight® on SAP ASE screen that provides more detailed information than what is available on the main window. Often contains graphs or tables that show ASE or Windows statistics or objects.

E

Engine

OS process running an Adaptive Server executable that communicates with one or more other Adaptive Server processes via shared memory. An engine can be considered as one logical CPU's worth of processing power. It does not represent a particular or physical CPU. It is sometimes also referred to as a server engine in ASE documentation.

Error log

A file that stores severe error messages and the results of the start-up and recovery of databases.

Error message

A message issued by Adaptive Server, usually to the user's terminal, when Adaptive Server detects an error condition.

F

FID

Family ID

H

Hit ratio

A ratio between logical accesses and physical accesses. Indicates how much work (I/O, compilation, etc.) is being saved by caching information in memory. Spotlight calculates all of its hit ratios using a differential sampling method.

I

I/O

Input or output to a peripheral device. In a database context, I/O refers to input or output to disk devices.

K

KPID

Kernel process ID

L

Lock

A concurrency control mechanism that protects the integrity of data and transaction results in a multiuser environment. Adaptive Server applies page or table locks to prevent two users from attempting to change the same data at the same time, and to prevent processes that are selecting data from reading data that is in the process of being changed. 

Locking

The process of restricting access to resources in a multiuser environment to maintain transactional isolation to prevent concurrent access problems. Adaptive Server automatically applies locks to tables, pages, or rows.

Log

An on-disk structure containing a record of a database's transactions. A log consists of one or more files.

Logical read

The process of accessing a data or index page already in memory to satisfy a query. See also physical read. Also known as Logical I/O. 

M 

MDAC

Microsoft Data Access Components. A layer of software that provides high-level software with the ability to communicate with ASE. Can be downloaded for free from Microsoft's Web site.

Metadata

Reserved area of memory used for tracking information on databases, indexes, or objects.

Metadata cache

A reserved area of memory used for tracking information on indexes, objects, or databases. The size of the metadata caches can be configured based on the number of metadata descriptions used by indexes, objects, or databases.  

Metadata description

A memory data structure that represents the state of an index, object, or database while it is in use or cached between uses. 

Metric

A unit of measurement that can be applied to a database. Metrics can help you gauge the performance of a system.

O

Object

A passive entity that contains or receives information, but which cannot change that information. In Adaptive Server, objects include rows, tables, databases, stored procedures, triggers, defaults, and views.

P

Paging

Disk I/O activity done by the operating system to manage its virtual memory. High paging rates can adversely affect performance.

Panel

A group of related components on the main Spotlight® on SAP ASE window.

Physical read

A disk I/O to access a data, index, or log page.

PID

Process ID. A unique number that identifies a Windows process at any given point in time.

Procedure

A collection of SQL statements and optional control-of-flow statements stored under a name. Adaptive Server-supplied procedures are called system procedures.

Procedure cache

An area of memory that ASE uses to store execution plans so that they can be reused, thereby avoiding recompiles.

R

RAID

Redundant Array of Inexpensive Disks. RAID is used to describe the configuration of multiple physical disks into one logical disk. Windows supports both hardware RAID and software RAID. The main types of RAID are:

RAID 0—Referred to as disk striping. Each part of the logical disk is spread out over multiple physical disks. Provides very good read and write performance, but no failure recovery.

RAID 1—Referred to as disk mirroring. Provides good recovery, but average performance.

RAID 5—Striping with parity. Good recovery, good read performance, but write performance is sub-optimal.

RAID 10—(RAID 0 + 1)—Striping and mirroring. Good recovery and read/write performance.

Recompile

The process of compiling a stored procedure part way through the procedure's execution.

Roles

Titles recognized by Adaptive Server that provide individual accountability for users performing system administration and security-related tasks in Adaptive Server. The System Administrator, System Security Officer, and Operator roles can be granted to individual server login accounts. Other roles can be created by the System Security Officer.

S 

sa

System Administrator. An ASE login that is created by ASE installation. sa is part of the SYSADMIN system role, and as such has full access within ASE.

Session

A single connection from a client application to ASE. Many applications will have multiple sessions open at any point in time.

Severity

Describes the level of importance of a threshold. A severity is user defined and determines how Spotlight behaves when the values for a metric fall within a range of values. For example, unusually high values might force a metric into a threshold with a high severity. This, in turn, could change the color of a component on the main screen, or play a sound.

Severity level number

A number between 10 and 24 that indicates the severity of an error condition.

SPID

Server process ID.

Spike

An abnormally high value in a dataflow or graph.
 

Spinner

A Spinner shows you the current level of activity for a statistic that is not directional. As the load increases, so too does the speed of the spin. If the statistic represented by the flow moves to another threshold, the spinner may change color. The combination of movement and color makes it easy to spot congested areas.

SQL

Structured Query Language. The language used to communicate with a relational database and that is the subject of standards set by several standards bodies.

sql.ini file

The interfaces file that contains definitions for each Adaptive Server to which your workstation can connect. The file must be on each machine from which clients connect to Adaptive Server. The file contains the name of the Adaptive Server, a list of services provided by Adaptive Server, and the port to use for connecting to Adaptive Server.

Synchronous read

A disk read I/O where the requester must wait for the disk read operation to complete. In ASE, the requesting session waits while the page is read from disk. This is normally the most common type of read operation in ASE.

Synchronous write

A disk write I/O where the requester must wait for the disk write operation to complete. Normally, ASE sessions do not wait for data and index write operations to complete. Most modifications to data and index pages are made in the Data Cache, and once the change has been recorded in the Log, the user can continue without having to wait for the data and index pages to be written to disk. However, there are some operations that can require the user to wait for the data and index writes to complete. This can be caused by operations such as create index, bulk insert, restore, etc. 

SYSADMIN role

The server role that has full access to all ASE facilities. By default, this role contains the sa login and the Windows "Administrators" group. To use Spotlight, you need to be a member of the SYSADMIN role.

System administration

A variety of tasks that includes, among other things, managing Adaptive Server's physical storage, creating and backing up databases, creating user accounts, granting permissions, and running diagnostic and repair functions.

System Administrator

A user in charge of Adaptive Server system administration, including managing disk storage, granting and revoking the System Administrator role, and creating new databases. The "sa" account, a single login, is created when Adaptive Server is installed. This login is configured with both the System Administrator and System Security Officer roles.

T

Temporary database

An ASE database used for temporary storage and work areas. All temporary tables and stored procedures reside here. More frequently referred to as tempdb.

Threshold

A range of values that may be returned by a metric. If the metric falls within this range, Spotlight checks the threshold's severity to determine how to behave. For example, the component representing this metric might change color.

Tool Tip

A message that appears whenever the mouse cursor moves over certain areas of the Spotlight window.

Transact_SQL

The SQL dialect used in SAP Adaptive Server.